What is the principal advantage of Teflon hose for use in an aircraft hydraulic system?

• A. Teflon hose retains its high strength under conditions of high temperature.
• B. Teflon hose is the lightest option available.
• C. Teflon hose resists chemical attack better than all others.
• D. Teflon hose is the cheapest.

Answer: (A)

In aircraft hydraulic systems, temperatures can rise significantly from both the fluid and the surrounding environment. The key advantage of PTFE hose is that it maintains its strength when the temperature goes up, so the hose is less likely to soften, stretch, or fail under pressure as heat increases. This mechanical stability at high temperature is what helps prevent leaks or bursts in critical hydraulic lines.

While the chemical resistance of PTFE is excellent and important in many contexts, the ability to retain strength at elevated temperatures is the most crucial factor for keeping hydraulic systems safe and reliable under operating conditions. The other options don’t capture this primary benefit as effectively: PTFE isn’t chosen mainly for being the lightest or the cheapest, and though it resists chemicals well, heat-related strength retention is the defining advantage in this application.